In 2012, Kim returned to the small screen opposite Han Ji-hye in May Queen, which depicts the success stories of people in the shipbuilding industry.[21][22] He later won the Top Excellence Award in a Serial Drama at the MBC Drama Awards (he also hosted the ceremony).[23] Kim was also the MC of Get It Beauty HOMME, a "beauty guide for men" on cable channel OnStyle.[24][25]

Though he initially became popular due to his fair skin and beaming smile (which earned the actor the somewhat feminine nickname of "smiling angel" among fans), in recent years Kim has cultivated an image as a tough guy. This physicality was showcased in his next drama, Scandal: A Shocking and Wrongful Incident (2013), where he played a detective who discovers that the man he considers his father had kidnapped him as a child from his biological family.[26]

In 2014, Kim joined Four Sons and One Daughter, a reality show with four male celebrities and one female guest star who form a family while living with fake parents in the countryside.[27][28] He also began hosting the current affairs program The Real Story Eye, which reconstructs cases to uncover the facts beneath rumors and speculation.[29] Later that year, he signed with a new talent agency, Will Entertainment.

Kim married Park Seo-yeon (who was three months pregnant at the time) on June 28, 2013 at Raum Wedding Hall in Yeoksam-dong, Seoul.[31] The couple were childhood friends who began dating in October 2012.[32][33][34][35] Park is the daughter of the head of an advertising agency, and she works in management at a modeling agency.[36] Their son, nicknamed "Heaven," was born in December 2013.[37][38]